一种多用户MIMO系统干扰对齐优化算法

An Optimization Algorithm of Interference Alignment for Multi-user MIMO Systems

干扰对齐技术可以获得干扰信道自由度的最佳值,从而有效改善系统的性能。在实际系统中干扰对齐技术通常采用迭代的方法进行预编码矩阵与干扰抑制矩阵的设计,而迭代方法都需要对发送预编码矩阵进行初始化处理。然而,目前大多数已有的研究所采用的初始化处理方法都忽略了干扰的影响。因此,在此基础上提出了一种基于新的初始化方法的优化算法,该方法在初始化预编码矩阵中既考虑了干扰信号也考虑了有用信号。首先,选取均方误差和最小化作为优化目标,然后利用正交三角(QR)分解将信道空间分为有用信号空间与干扰信号空间来进行预编码矩阵的初始化设计,经过反复迭代得到发送预编码矩阵与干扰抑制矩阵的最优解。理论分析和仿真结果表明,所提算法在收敛性、均方误差、和速率等方面都优于其他算法。

Interference alignment technology can effectively improve the system performance by gaining the optimal freedom values of interference channels.The iteration methods are usually employed to design the precoding matrix and interference suppression matrix for interference alignment technology in practical systems,while initialization of the precoding matrix is necessary in iteration methods.However,most recent researches ignore the interference effect in initializing the precoding matrix.Therefore,motivated by this,an optimization algorithm with a novel initialization method is proposed by considering both the useful signal and the interference signal.The mean square error minimization is firstly selected as the optimization goal.Then,the Quadrature Rectangular(QR)decomposition in initializing the precoding matrix is used to divide the signal space into the useful space and the interference one.Theoretical analysis and simulations show that the proposed algorithm surpasses other existing algorithms in convergence,minimum mean square error,and achievable rate.